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The truth about Trevon Diggs: Sorting out Cowboys CB's 'boom or bust' season

Snagging seven interceptions in six games should do a lot for the stock of a young player.

And it sure seems like Cowboys cornerback Trevon Diggs is riding his run of success to the moon, racking up picks at that incredible clip to set himself up as a potential Defensive Player of the Year candidate.

But there's at least one analytical outlet taking a more skeptical view: Pro Football Focus, which has graded Diggs as the 61st-best corner through the 2021 NFL season's first seven weeks.

The average football fan might find themselves at a loss when attempting to understand this grade for a player who leads the league in targeted EPA, per Next Gen Stats -- Diggs' mark of -37.7 points is more than twice that of the next closest defender in the category.

How could someone who does so much to help his team rank so low in PFF's eyes? And, perhaps more importantly, what does that discrepancy tell us about who Diggs really is?

"The first thing is that interceptions are not a great way of measuring cornerback performance, or any performance, to be honest," Sam Monson, PFF's lead analyst, said this week. "It's a really small sample size of plays, and it doesn't always tell the whole story."

PFF grades players on a per-play basis, working on a scale of -2 to 2 in increments of 0.5. Most plays for most players end up at expectation -- or 0, on PFF's scale. And while plays resulting in a takeaway will understandably produce a better grade, it's about more than totals for the folks at PFF, who don't simply scan the box score when evaluating any one player.

"We all assume that every single pick is created equal and they're all plays by defenders, but a lot of them are not," Monson said. "A lot of them are plays where there's a bit of luck involved, or it's a bad read by a quarterback and it's kind of thrown straight to a corner. Trevon Diggs has got a little bit of all of those. He's made some incredible plays, some incredible interceptions so far this season. He's also had a couple where the ball has just kind of found him. That tends to happen any time any player has a ton of interceptions. You're going to find a few plays that bounce in his direction, because even the best players in the NFL, you just don't get that volume of interceptions by being great. It doesn't happen.

"It's why even guys we think of that are amazing ballhawks, like Antonio Cromartie or Asante Samuel or any of those great corners, they don't tend to have back-to-back-to-back-to-back 10-interception seasons. It tends to happen once because they have like their usual year, and then they get a bit of luck bouncing in their direction. That's where those extra interceptions come from."

Think of Diggs' pick-six in Week 3 against Philadelphia. Eagles quarterback Jalen Hurts fired the ball to DeVonta Smith, who was running a quick out. Smith stumbled and fell to the ground, which stopped him from coming back to the ball and opened a highway the width of the 405 for Diggs to sprint down underneath the pass, intercept it and return it for a touchdown.

"Those are the kinds of things that turn a contested catch into a pick-six," Monson explained. "One of those is going to get a lot more attention from people than the other."

Or consider Diggs' first pick against the Carolina Panthers in Week 4. Having dropped into zone coverage on the play, Diggs was in the perfect place to interrupt what turned out to be a poor decision made by Sam Darnold to throw the ball into traffic. Reading the eyes of Darnold, all Diggs had to do was swivel his hips to his left, take one step, jump and catch a layup of an interception.

The flip side of these golden opportunities are the plays where Diggs uses his closing speed to erase separation and make a play on the ball. His second interception against Carolina was a prime example of this. When Dallas deployed a man free coverage, Diggs gave D.J. Moore 9 yards of cushion at the snap, then drove down on a pass intended for Moore, who was running a hitch route. Diggs sprinted in front of Moore and corralled Darnold's throw.

Diggs entered the NFL as a second-round pick in 2020 with a résumé built on his innate sense for the football, an ability derived from a past that included time spent as a wide receiver. NFL.com's Lance Zierlein effectively nailed his scouting report on Diggs ahead of the draft with a handful of notes that have clearly carried over to the professional level:

  • Eyes recognize route-jumping opportunities
  • Little wasted motion to plant, drive and close
  • Wide receiver's instincts and catch talent
  • Used ball skills to make baller interceptions this season

Those have been Diggs' defining characteristics in his second NFL season. His pick-six of Patriots rookie Mac Jones in Week 6, interception No. 7 on the year, relied heavily on these abilities. It started with a bit of the luck Monson mentioned, with the ball deflecting off the hands of Kendrick Bourne and ending up in front of Diggs' face. Then, it was all about reacting instinctively. See ball, get ball -- and Diggs certainly got it, hauling in the tipped pass, leaping over Bourne and winning the race to the end zone.

Plays like that are what get defensive-minded fans' salivary glands cooking. The plays in between, though, are what make up the vast majority of PFF's defensive grade for Diggs, and they illustrate where there is room for improvement.

"I've seen some people refer to Diggs as 'cornerback Jameis Winston,' " Monson said. "It's a facetious joke, but there's a little bit of truth in it as well. He's made some incredible plays and obviously multiple defensive touchdowns; he's put points on the board. But's he's also ranked like fourth in the NFL in terms of yardage given up in coverage, and Dallas was on a bye week [in Week 7]. So he's played a game less than a lot of these guys. He's third in the NFL in terms of yards per catch given up. He's given up 19 yards per reception. So when he gets beat, it can be pretty ugly."

Diggs' weaknesses from Zierlein's scouting report have also carried over. One -- struggles to stay in phase with double moves -- popped up immediately after his pick-six against New England. Bourne ran an out-and-up, winning the inside against Diggs, while safety Damontae Kazee floated out of position, taking a poor angle (and nearly taking out Diggs) over the top. The combination allowed Bourne to catch the ball inside both of them and sprint for a 75-yard touchdown.

Coverage inconsistencies like that have been common for Diggs. They're not unexpected for a player in his second NFL season, and his first under new coordinator Dan Quinn. But Diggs is also weak against the run -- he's earned PFF's worst run defense grade among 120 qualifying corners (29.9).

"You have to ignore quite a lot of bad if you want to turn Trevon Diggs into a Defensive Player of the Year candidate," Monson said.

That doesn't mean Diggs isn't a good corner with the potential to become great. Quinn seems to have simplified things for the Cowboys after a season in which, as Monson said, they were trying to do too much scheme-wise, leading to confusion at every level of the defense and leaving the unit open to get gashed repeatedly. This year, the defense is playing better, and Diggs -- who finished his rookie year with just three picks -- has been making the splash plays to flip momentum in Dallas' favor.

He's also jumped into the national conversation, even if he's not yet, at this point in his young career, as consistently effective as big-name corners tend to be.

"Any time a corner is making that many plays on the ball, I think his perception is automatically pretty sky high," Monson said. "It takes a little bit of time for that to level out to where he's likely to be long term. But I think as much as it seems obvious and everybody fights against it, I think it's still very hard for the NFL to overlook guys who get gaudy sack numbers and interception totals."

Is Diggs a legitimate Defensive Player of the Year candidate? The counting stats seem to suggest he has a shot; the last defensive back to win the award, Stephon Gilmore, did so in 2019 by tying for the league lead in interceptions with six as part of the Patriots' No. 1-ranked defense.

Gilmore also earned PFF's fifth-best defensive grade among cornerbacks that season. By contrast, Diggs is succeeding with what Monson called "massively high-variance stuff," associated with "a lot of boom or bust."

Then again, capturing one of the NFL's highest individual honors would be quite the boom.

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